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May 4 1926. 4 1,583,197

- C. F. STODDARD EXPRESSION MECHANISM FOR PLAYER PIANOS May 4', 1926. 1,583,197

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. C. F. .STODDARD zxranssrou macrmmsm FOR PLAYER PIANOS 5 Sheets-Shet 5 Filed Oct. 15, 1923 Patented May 4,

UNITED STATES CHARLES F. STODDAED, OE NET-if YORK,

PATENT OFFEQE.

N. '55., ASSZGNOR TO AMERICAN PIANO COM- PANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

EXPRESSION MECHANISM FOR PLAYER PIANOS.

Application filed October 15, 1923.

To all whom it 77 12 concern:

Be it known that I, CHAnLns F. Sronnann, a citizen of the United States, and a resident of the city of New York, county of 5 New York, and State of New York, have 19 cal instruments and pertains more particularly to expression mechanisms for the same.

It is an object of this invention to provide a unitary expression mechanism which may be assembled as a unit for installation in a piano.

Other objects and advantages of the invention will appear hereinafter.

A preferred embodiment of the invention selected for purposes of illustration is shown in the accompanying drawings, in which,

Figure 1 is a front elevation of the device,

Figures 2 and 3 are left and right side elevations respectively,

Figure 1 is a longitudinal section,

Figure 5 is a top plan view,

Figure 6 is a. section on the line 66 of Figure 1.

Referring to the drawings, the device may be conveniently mounted on any suitable part of a piano f'ame by means of a block 1 to which is secured a valve block 2 in which is formed a valve chamber 3 through which the passage of air is controlled by a throttle valve at, adapted to cooperate with one end of a short cylindrical tube 5 as a valve seat. T hetube 5 also forms a passage leading from the valve chamber 3 to a passage 6 connected by a conduit 7 to an equalizer, not shown.

The valve 1 may be of any suitable construction, that shown here comprising a valve disk 8 rotatably secured between a pair of collars 8 mounted on a valve stem 9. The valve stem 9 is slidably held in a pair of sleeves 10 and 10, the sleeve 10 being inserted in the valve block 2 and the sleeve 10 being inserted in a supporting frame 11 secured to the valve block 2.

The passage 6 passes entirely through the valve block 2 and is connected at its other end with a conduit 12 leading to a suitable player action not shown. The valve cham ber 3 is connected with an exhaust pump through a conduit 13 leading to a tube 14.

The valve 4 serves, as is well understood,

Serial No. 668,456.

a throttle valve to control communication between the player actions and by the pump. The air in the passage 6 is accordingly known as regulated air because itis regulated by the valve 4 to the pressure desired to operate the player pneumatics at any particular time.

Mechanisms are provided for controlling the operation of the valve 4 in order that the pressure of the regulated air in the passage 6, and consequently in the player actions, may be maintained at or adjusted to any desired level. bellows pneumatics20, 21 and 22, each having a fixed leaf 23 secured to the frame member 11 and a movable leaf 24 secured to a bellows board 25 pivoted at 26 to a block 27 alsocmounted on the frame member 11.

The valve stem 9 is mounted, as shown in Figure at, to contact with the bellows board 25 so that movement of the bellows board 25 induced by movement of the bellows pneumatics 20, 21 or 22 will impart a movement to the valve stem and valve. Movement of the arm 25 is limited in one direction'by contact of the valve disk 8 with the collar 5 and movement in the other direction is limited by the limit stop 28 secured to the frame member 11.

Each of the pneumatics 20, 21 and 22 is connected by a tube 30 with suitable controlling valve mechanismsxwhich maybe similar to those in Patent No. 1,4:09A79, of

March 1 1, 1922. As set forththerein th'ese valves control the admission of atmospheric air or regulated exhaust to the bellows pneumatics. For softest playing the bellows pneumatics will all be subjected to regulated exhaust to bias the valve at toward its valve seat 5. bellows pneumatics will all be open to atmospheric air to lessen the force tending to bias the valve toward its seat.

Various combinations of the pneumatics 20, 21 and 22 may be effected by suitable operation of the controlling valves to bias the valve 1 toward its seat with varying forces to thereby establish a scale ofplaying intensities graduated in suitable steps or increments from lowest playing intensity to the highest. As is also set forth in the aforesaid patent the valve l and the pneumatics 20, 21 and 22 perform a regulating function, to maintain any given intensity at a constant level whether one or many notes Such means includes the threev Conversely for loud playing the are sounded, due to the fact that the valve chest is connected to regulated air.

A spring 35 is provided to bias the valve 1 in the opposite direction to the force ap plied by the pneumatics 20, 21 and 22. One end of the spring 35 is connected by a screw 36 to a lever 37 pivoted at 33 to a block 39 secured to the valve block 2, the other end of the lever extending outwardly to contact with the end of the valve stem as at 4-0. The other end of the spring 35 is connected by a screw 41 to a lever 4L2 pivoted at 43 to a block 44: fixed to the valve block 2.

An adjusting screw 45 bears against the lever 42 to adjust the spring 35 to any desired tension when the pneumatics 20, 21 and 22 are all subjected to exhaust to produce softest intensities in the instrument. This base intensity may be adjusted to the de sired degree of loudness by suitable adjustment of the screw 45.

The mechanisms thus far described have the capacity to produce incremental changes in tone intensity and to adjustthe base value of said intensities to the desired level. As an additional means of affecting tone intensities in order to produce continuously progressive changes in tone intensity, the bellows pneumatic is provided, the force of which is applied to the valve l to modify the degree of exhaust applied to the player pneumatics. This pneumatic comprises a fixed leaf 51 secured to a frame 11 and a movable leaf 52 pivoted thereto. A flat spring 53 is secured to the movable leaf 52 and extends outwardly therefrom into proximity with the bellows board 25. The bellows board carries a U-shaped bridge member 54 under which the end of the flat spring may project.

During normal operation of the arm 25 by the bellows pneumatics 20, 21 and 22, the spring 53 does not contact with the bridge 54; but when the pneumatic 50 is exhausted through the tube 55, the flat spring 53 is swung outwardly against the bridge 5 f to impart an additional yielding force tending to bias the valve 4 away from its seat.

The collapse of the pneumatic 50 may be controlled by any suitable valve mechanism, preferably a two speed valve mechanism such as that illustrated in Patent No. 1,d09, 192 of March 14, 1922 which serves, as explained therein, to collapse the pneumatic 50 either rapidly or slowly to thereby secure crescendo effects by the rapid or slow increase in tension on the valve 4 by the spring 53.

In the preferred embodiment illustrated the pneumatic 50 is provided with a toggle comprising a pair of levers 56 and 57, the lever 56 being pivoted to the movable leaf at 58 and the lever 57 being pivoted to the fixed leaf at 59, the two levers being pivoted to each other at 60. A coil spring 61 is connected to the toggle at 62 and to the movable leaf at 63.

The toggle serves as a compensating device to compensate for the loss in pneumatic power as the bellows collapses, due to the folding of the bellows cloth, and also for the increase in the tension of the spring due to the greater expansion thereof by causing the spring to act through a progressively decreasing moment of force as the bellows collapses, the result of the action being that the bellows is collapsed or expanded at a constant rate of speed due to the equalization of the forces tending to produce collapse or expansion.

As a still further means of controlling the valve 4, and consequently the suction ap plied to the player actions, a hand lever is provided extending through the key bed 71 for convenient manual operation. The hand lever 70 is secured to a shaft 7 2 to which is also secured a lever 7 3 to one end of which is connected a spring 74:. The other end of the spring 74 is connected to a screw 75 mounted in one arm of a bell crank 75 pivoted at 77 to block 78 secured to the valve block 2. An additional spring 79 is connected to the same arm of the bell crank 76 and has its other end fixed to valve block 2 at 80. The other arm 81 of the bell crank 76 extends into proximity with the lever 37 before described, but is so arranged that it is normally out of contact therewith and only contacts therewith when the hand lever 70 is rotated in counter-clockwise direction to tension the spring 7 1. It will be apparent that when the arm 81 contacts with the lever 37 through such movement, the valve 4 will be biased toward open position to increase playing intensities.

In operation, the device is assembled as shown in the drawings for insertion in a piano. The tube 7 is connected to an equalizer, tube 12 is connected to the player actions, tube 14 is connected to a suitable source of exhaust, tubes 30 are connected to their controlling valves, and tube 55 is connected to its controlling valves. When the pump is started to exhaust the pneumatic system, the pneumatics 20, 21 and 22 will be open to exhaust as explained in Patent No. 1,409379 before referred to to bias the valve toward its seat against the tension of the spring 35.

hen the apparatus is in this condition, the screw 45 may be turned to adjust the spring 35 to the correct tension to maintain the lowest intensity which it is desired to maintain in the instrument. It will be observed that under these conditions the tension of the spring 35 is the only mechanical force tending to open the valve, the flatsprin 53 and the bell crank 76 both being free Irom mechanical contact therewith.

W hen it is desired to produce incremental changes in playing intensities, the pueu matics 20, 21 and 22 are operated by their controlling valves to bias the valve 4 more or less toward its valve seat. If it is desired to produce a crescendo eii'ect, the pneumatic is collapsed under controlot' its controlling valves to bias the valve away from its seat. The operations so far described are entirely automatic, the valves controlling the pneumatics 20,21 and 22, and the pneumatic 50 being controlled from a suitable note sheet.

If it is desired to consciously modify the automatic expression, or if it is desired to control the expression independently of the automatic expression controlling means, the hand lever may be moved to control the valve d in any desired manner.

It is to be understood that the invention is not limited to the embodiment herein shown for purposes of illustration, but that on the contrary it may be variously modified and embodied within the scope of the sul joined claims.

I claim as my invention:

1. In an automatic musical instrument having a main source of power and player pneumatics, in combination, a throttle valve interposed between said source of power and player pneumatics; pneumatic means to bias said valve toward closed position; yielding means to bias said valve toward open position; means to adjust said yielding means to any desired tension; and additional pneumatic means, normally disconnected from said valve, to bias said valve toward open position.

2. In an automatic musical instrument having a main source of power and player pneumatics, in combination, a throttle valve interposed between said source of power and player pneumatics; pneumatic means to bias said valve toward closed position; yielding means to bias said valve toward open position; means to adjust said yielding means to any desired tension; and manually operated means, normally disconnected from said valve, to bias said valve toward open position.

3. In an automatic musical instrument having a main source of power and player pneumatics, in combination, a throttle valve interposed between said source of power and player pneumatics; pneumatic means to bias said valve toward closed position; yielding means to bias said valve toward open position; means to adjust said yielding means to any desired tension; additional pneumatic means, normally disconnected from said valve, to bias said valve toward open position; and manually operated means normally disconnected from said valve to bias said valve toward open position.

4:. In an automatic musical instrument having a main source of power and player pneumatics, in combination, a throttle valve interposed between said source of power and player pneumatics; means to operate said valve to vary by perceptible increments the degree of power applied to said player pneumatics; means to adjust the base value of said increments to any desired intensity; means normally disconnected from said valve'to operate said valve to vary the degree of power applied to said pneuinatics by substantially continuous progression.

5. In an automatic musical instrument having a main source of power and player pneumatics, in combination, a throttle valve interposed between said source of power and player pneumatics; means to operate said valve to vary by perceptible increments the degree of power applied to said player pneumatics; means to adjust the base value of said increments to any desired intensity; and manually operated means normally disconnected from said valve to vary the de gree of power applied to said player actions.

6. In an automatic musical instrument having a main source of power and player pneumatics, in combination, a throttle valve interposed between said source of power and player pneumatics; means to operate said valve to vary by perceptible increments the degree of power applied to said player pneumatics; means to adjust the base value of said increments to any desired intensity;

means normally disconnected from saidvalve to operate said valve to vary the degree of power applied to said pneumatics by substantially continuous progression; and manually operated means normally disconnected from said valve to vary the degree of power applied to said player actions.

7. In an automatic musical instrument having a main source of power and player pneumatics, in combination, a throttle valve interposed between said source of power and player pneumatics; yielding means to bias said valve toward open position comprising a pivoted lever having one end contacting with said valve; a second pivoted lever; a spring connecting said levers; and means to move said second pivoted lever to adjust the tension of said spring.

8. In an automatic musical instrument having a main source of power and player pneumatics, in combination, a throttle valve interposed between said source of power and player pneumatics; and means to operate said valve, comprising a pneumatic and yielding means normally disconnected from said valve to operatively connect said pneumatic and valve.

9. In an automatic musical instrument having a main source of power and player pneumatics, in combination, a throttle valve interposed between said source of power and player pneumatics; and means to operate said valve, comprising manually operated means normally disconnected from said valve.

10. In an automatic musical instrument having a main source of power and player pneumatics, in combination, a throttle valve interposed between said source of power and player neumatics, means to operate said valve, comprising yielding means normallyi,fi83,197 

